Boiler drum



April. 10, 1934.

I. L. LANGVAND 1,954,631

BOILER DRUM Filed Sept. 6, 1930 Figff INVENTOR A Z 0723142725 A TORNEY Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE BOILER DRUM Application September 6, 1930, Serial No. 480,138

4 Claims.

steam.

An object of this invention is to provide a drum of the type set forth, constructed and arranged to permit its manufacture with a single longitudinal seam.

Other objects will be apparent to those skilled in this particular art from the description in the specification in connection with the drawing, in which Fig. 1 is a perspective view of a drum embodying this invention with parts broken away;

Fig. 2 is a fragmentary end view in cross section showing the seam through an end weld;

Fig. 3 is a fragmentary end view in cross section showing the seam through an intermediate point;

Fig. 4 is a fragmentary end view in cross section showing the seam through an intermediate weld point;

Fig. 5 is an end View partly in section through an end weld showing the seam and its location on the complete drum.

One embodiment of the invention is illustrated in Figs. 1 to 5 in which the drum 1 is shown formed from a single metallic sheet bent to a point where its longitudinal edges 2 are spaced apart a small distance. A filler strip 3 is positioned longitudinally of the drum between the spaced edges 2 and is welded thereto at the ends 11 and 14 and at intermediate points 12 and 13. The welds 11 and 14 extend some distance longitudinally of the seam and form a steam-tight joint at each end of the drum. Intermediate welds 12 and 13 are spot welded as shown, and give strength to the structure during its assembly, to be described later.

In the assembly of the drum, after the welding is completed, the butt straps 5 are bolted in place and drilled for riveting. After the parts have been drilled the butt straps are removed and cleaned and then replaced and riveted. The

welded seam is such as to insure there will be no springing of any part of the drum shell with the accompanying misalignment of rivet holes while this procedure is going on.

In practice it is most desirable to utilize a drum construction with a single longitudinal seam, however, in view of the thickness of the metal which must be used to insure the proper strength of a boiler drum used under high pressure conditions, it has been found to be impractical hitherto to bend a single heavy sheet to an extent that its longitudinal ends were abutted sufficiently to enable them to be welded.

It will be apparent that the present invention provides a drum having a seam of such arrangement that a single butt strap only is employed on each of the inner and outer faces of the drum.

Preferred embodiments of the invention have been described, but it is obvious that changes may be made therein without departing from the spirit and scope of the appended claims.

I claim:-

1. A boiler drum comprising a sheet bent to substantially cylindrical form with its longitudinal edges spaced apart, a metal strip of substantially the same length and thickness as the bent metallic sheet disposed between the longitudinal edges of the sheet and welded thereto, butt straps on the inner and outer sides of the cylindrically bent sheet, said butt straps being riveted to the adjacent longitudinal edges of the sheet.

2. A single plate rolled to approximately drum form, a joining strip between the adjacent edges of the plate and welded thereto to avoid the ten- 30 sion required to close the space between the plate edges and complete the required drum form, and a riveted butt strap overlying the edges and strip, some of the rivets extending through said strip and others through the edges of the plate.

3. A tension-free curved metal section having a longitudinal opening, said opening butt-jointed with a wall section strip between the edges of the opening, each side thereof formed with the edges of the opening to provide grooves and dams for molten metal, a metal deposit in the grooves uniting the aforesaid parts, butt-joint straps on opposite sides of the joint, and rivets through the plates and metal sections.

4. A tension-free curved metal section having a longitudinal opening, said opening butt-jointed with a wall section strip between the edges of the opening, each longitudinal corner edge thereof shaped and cooperating with the shaped complemental edge of the curved section opening to provide grooves and dams for molten metal, a molten metal deposit in the groove uniting the aforesaid parts, butt-joint straps on opposite sides of the joint, and rivets through the plates and metal sections.

' IVAR LAURITS LANGVAND. 

